1. Field of the Invention
The present invention relates to a device for interchanging displays in a digital camera, and more precisely to a device for interchanging displays in a digital camera whereby the method of display changes between displaying the image with a built-in liquid crystal device and displaying it on a monitor device by linking the camera to the monitor device with the help of a video cable, and between when focusing and not focusing.
2. Description of the Related Art
Some digital cameras, in addition to having a small liquid crystal or other display device, have an image output terminal whereby image signals are fed to an external monitor device. With digital cameras, insofar as the image is being viewed on the liquid crystal display device, the screen is relatively small and it does not detract very much from the quality of the image even if it is displayed using an image signal which has been processed so as to cull a large number of pixels. However, this is not so if an image signal of this sort is used to display the image on a monitor device with a large screen.
The situation is that especially where the image is processed by means of a microprocessor, it is possible to shorten the time required for processing in direct proportion to the number of pixels that are culled.
Conventional digital cameras have made use of image signals from the same image processing circuit irrespective of whether the image is viewed on the liquid crystal display device built into the camera or on an external monitor device. Consequently, with a conventional digital camera where the image processing circuit of the camera is one which culls large numbers of pixels during image processing, the image has been rough and the quality defective when viewed on an external monitor device using a video cable. Conversely, if the image processing circuit of the camera does not cull large numbers of pixels, it takes a long time to process the image, so that there is a long interval between frames in the quasi-dynamic image displayed on the liquid crystal display device of the digital camera.
Moreover, if the same tone is employed when displaying the image signal on a liquid crystal display device as when displaying it on an external monitor, it can become difficult to see the liquid display device, particularly when photographing in bright light outdoors.
Furthermore, when adjusting the focus manually, the user does so while viewing the image displayed on the liquid crystal display. This can be problematic in that the extreme smallness of the display makes it difficult to decide whether or not it is in focus.
With a view to solving the abovementioned problems, it is a first object of the present invention to provide a digital camera with interchangeable displays wherein large numbers of pixels are culled in processing the image signal which is output for display on the display device which is built into the camera, while a smaller number are culled in processing the image signal which is output for display on an external monitor device using a video cable.
Moreover, it is a second object of the present invention to provide a digital camera with interchangeable displays wherein contrast is emphasized in processing the image signal which is output for display on the display device which is built into the camera, while reproduction of tone is emphasized in processing the image signal which is output for display on an external monitor device using a video cable.
Furthermore, it is a third object of the present invention to provide a digital camera with interchangeable displays wherein during adjustment of the focus an image signal is output which is processed in such a manner that part of the image is enlarged.
In order to attain the abovementioned objects, the present invention is a digital camera having a built-in display device and an image output terminal which transmits image signals to an external monitor device, and comprising means for changing the position of the focus, means for detecting the position of the focus, means for detecting whether or not the video cable has been inserted, means for changing the method of processing employed in the means for processing the image, and a method of feeding the output of the means for processing the image to the image output terminal.
The above configuration permits the realization of a digital camera with interchangeable displays wherein large numbers of pixels are culled and the image signal is processed at high speed when it is being output for display on the display device which is built into the camera, while a smaller number of pixels are culled with higher image quality when processing the image signal which is output for display on an external monitor device using a video cable.
Moreover, it permits the realization of a digital camera with interchangeable displays wherein contrast is emphasized in processing the image signal which is output for display on the display device which is built into the camera, while reproduction of tone is emphasized in processing the image signal which is output for display on an external monitor device using a video cable.
Furthermore, it permits the realization of a digital camera with interchangeable displays wherein during adjustment of the focus an image signal is output which is processed in such a manner that part of the image is enlarged.